Yes, please. I'll wait, but I'm curious about where that number came from.
Just before I hit the sack... Islamic economic jurisprudence
The 2.5% is from the "zakat", It was not called demurrage but it certainly fit the definition. The article called "zakat" as tax. But it differs from tax because you are not required to pay it to specific authority for redistribution as services. You can do it yourself or pay someone to do it for you. This "Zakat" was for specific possessions (Cattle, Precious metals and else) which are kept and not spent in a specific period of time (a year mostly).
P.S. Yes there is no such thing as "Interest rate" in Islam. It is forbidden.
This would make a very interesting topic in the economics forums. But for now I have to sleep to wake up to the already opened netbeans instance -_-!
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